618 FXUS63 KEAX 141757 AFDEAX AREA FORECAST DISCUSSION National Weather Service Kansas City/Pleasant Hill MO 1257 PM CDT Wed Aug 14 2019 .Discussion... Issued at 335 AM CDT WED AUG 14 2019 The weather for today looks fantastic for mid August. High temperatures should climb into the low to middle 80s with afternoon dewpoints in the low to mid 60s. With high pressure building into the area, dry weather is expected. We should see similar, perhaps a bit warmer, temperatures on Thursday. The bigger issue for Thursday will be potential for several rounds of precipitation. The upper level pattern shows northwesterly flow. There is decent agreement in the models in developing an MCS in western Nebraska this evening/tonight that would then track to the southeast and move into the area Thursday morning before dissipating by late morning. There's still a fair amount of uncertainty with this, especially how far southeast it may track into the day. But feel that increasing PoPs to around 50% is reasonable at this time for mainly northern Missouri. Thursday night into Friday, there is a stronger signal for an MCS to track across the area. A mid to upper-level shortwave will track across the region with a strong low level jet transporting copious moisture northward. Overnight, PWAT values increase to around or just over 2". This is right around the average max value based on sounding climatology. So the ingredients for heavy rainfall are coming together. This looks most likely across northern MO at this time. Have increased PoPs for Thursday night into Friday morning. Depending on how this MCS evolves into the day on Friday, there may be another, potentially severe MCS develop Friday evening/night. There is a fair amount of uncertainty in how the earlier convection will affect the airmass later in the day and where any boundaries may end up. But along and south of any boundary, strong instability should develop. In the mid to upper- levels a shortwave trough will track north of the region. Fairly strong mid to upper-level flow will be present with 30 to 40 kt flow around 700mb, increasing to 50 to 60 kt flow at 250 mb. A strong low-level jet is expected to develop after 00Z Friday, transporting additional moisture northward and enhancing low-level shear. With the stronger mid and upper-level winds, 0-6km shear of 40 to 50 kts is possible. Given the combination of CAPE and shear, severe weather looks quite possible Friday evening. But again, the main question will be how the convection from earlier in the day impacts later convection. The active weather pattern may continue Saturday evening and overnight into Sunday. Broad upper troughing will track across the northern Plains. Again, a strong low level jet develops and allows ample moisture to advect into the region. All of this may interact with a frontal boundary in the area and lead to additional strong to potentially severe storms. With all of these multiple rounds of storms, the most likely areas to see heavy rain, with this suite of models and forecast, look to be along and north of the Missouri river. This area could see widespread 2 to 4 inch rainfalls with likely locally higher amounts depending on where storms actually develop and track. && .Aviation...(For the 18Z TAFS through 18Z Thursday Afternoon) Issued at 1255 PM CDT WED AUG 14 2019 Today and tonight looks to be rather quiet for the airports. However, STJ may experience some potential fog tomorrow morning as dewpoints could dip in the early morning. Other airports have potential for some early morning fog, but due to the nature of STJ being located within a valley and its history was only confident adding that to their TAF for some early morning fog. At the end of the TAF period, there could be some potential showers rolling into the area from the northwest that STJ will experience primarily. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ Discussion...CDB Aviation...Barham/Green